1. Field of the Invention
The present invention is directed to a child resistant closure for containers having threaded necks. More specifically, it is directed to a child resistant closure which involves an inner and an outer cap which easily close by way of ratchets but require certain movements to engage the inner cap and outer cap to effect opening of the closure.
2. Prior Art Statement
There are truly many hundreds of patents covering variations on child proof closures. Many of these rely upon the use of inner caps and outer caps coupled with ratchet engagement and disengagement for closing and more difficult opening. Indeed, the child resistant cap which is currently most popular involves the use of an inner cap and an outer cap with ratchets that easily engage for closing but require substantial downward force for opening. While this is advantageous in preventing small children from opening medicine containers, it creates serious difficulties for the aged, for people with grip or strength difficulties such as people with arthritis, as well as other types of manual dexterity problems. The present invention is directed toward overcoming the strength requirements while still maintaining a child resistant feature. Significantly, the present invention achieves this by way of a cap which requires only two molded parts in its preferred embodiments.
U.S. Pat. No. 2,908,413 issued to T. J. O'Donnell on Oct. 13, 1959 describes a safety cap which involves an outer cap and an inner ring whereby the bumps or protrusions on the inner cap must be aligned with a slot or opening in a ring on the neck of a threaded bottle in order for the outer cap itself to be effectively unscrewed. This is similar to the present invention in that it requires an alignment of protrusions and subsequent lifting and turning. However, O'Donnell requires manual resetting and realignment in order to properly secure the cap and, in those cases where the protrusions are not aligned, the outer cap may be rotated and cause stresses to the ring thereby damaging the cap. Importantly, O'Donnell is completely lacking in any automatic reset of the safety feature of that device.
U.S. Pat. No. 3,468,444 issued to J. Martin, Jr. on Sep. 23, 1969 is also directed to an inner cap and an outer cap. In this particular invention, the outer cap and inner cap must be properly aligned by setting indexes to one another and then the outer cap must be squeezed so that protrusions fit into recesses in the inner cap so that the inner cap may be engaged for removal. Unfortunately, this invention requires squeezing for opening and closing and does not contribute to overcoming the problem that arthritics and other people who have diminished dexterity and strength would experience. Further, the Martin invention requires alignment and squeezing for retightening the inner cap onto the container.
U.S. Pat. No. 3,447,709 issued to V. Marasco on Jun. 3, 1969 describes a locking cap for bottles which involves the traversal of a particular track coupled with a release type lever or pin. This release handle involves a complicated device and requires a single digit use to effect opening. Further, the device involves complex manufacturing techniques which would be eliminated by the present invention.
U.S. Pat. No. 3,656,645 issued to John Fontenelli on Apr. 18, 1972 describes a two piece safety closure cap which involves a top cap and a ring with engagement of the lip of a container whereby tracks are utilized and proper alignment is necessary in order to open the cap. However, this does not involve the type of arrangement utilized in the present invention where protrusions must be properly aligned and then moved into a keyway slot in order to enable an inner cap and outer cap to rotate together in an opening fashion.
U.S. Pat. No. 4,779,747 issued on Oct. 25, 1988 to Simone Morel involves a container with a three piece safety closure which requires alignments of the three parts so that the top cap may be rotatably removed from the neck of the container. While this invention involves some alignment, it does not involve a keyway slot and requires three components and alignment of these three components in order to effectuate opening of the closure.
Thus, notwithstanding the tremendous quantity of ideas and patents covering safety closures, it is believed that none of the prior art teaches or renders obvious the present invention which involves the use of a keyway system for proper engagement of an inner cap and a outer cap to create a child resistant closure which will be easily operated by users with low strength or weak manual capabilities.